Automatic fire-extinguishing system



1934- E. A. LOWE ET AL AUTOMATIC FIRE EXTINGUISHING SYSTEM 9 Lu 2 0 Z 67 3 3 2 3 3 O 4 7 3 5 6 53 5. o U 0 3 3 6 4/ m O I 0 7 Z A 0 I QINVENTORS Ernesz 14. Lowe Jo/m R. //a Won 5% ffi WMM ATTORNEYS PatentedJan. 9, 1934 UNITED. STATES J'P'ATENT OFFICE AUTOMATIC.FIRE-EXTINGUISHING SYSTEM ration of Delaware Application January'26,

26 Claims.

The present invention relates to fire extin-. guishing systems and moreparticularly to that form of. the-same wherein the supply of the fireextinguishing fluid to the system iscontrolled by means responsive to adecrease of the normal pressure in the system consequent upon theopening of a sprinkler head or other outlet thermostatically controlled.

In the preferred system embodying our present invention the pressureacting upon the means supplying the extinguishing fluid or medium is airand acts upon a main valve in away topress the same to its seat, theopening of saidvalve in response to the decrease of air pressure beingeffective to cause water or similar medium to pass into the distributingpiping, for emission through the head or outlet in the fire Zone tocontrol or extinguish the. fire.

The invention will accordingly be described as carried out in connectionwith such. a preferred system. and also for purposes of illustration theopening. of the outlet will be described as automatically produced bythe action of a fuse or fusible. device which releases the: normallyclosed outlet. valve upon the attainment of a fixed or determinate.temperature sufiicient to melt or soften the fuse. so that it shall notbe longer efiective to keep the outlet in closed position.

The principal object of our. invention is, gener-- ally speaking, to.expedite the arrival of the fire extinguishing medium at the outlet orsprinkler head. upon the occurrence of fire or other abnormal thermiccondition and to this end the invention consists essentially in theprovision of means in connection withthe control, valve or means forsupplying fluid extinguishing medium to the pipes upon a drop inpressure in the pip.- ing, of supplemental means forcausing said valveto open or function by operation of thermally responsive means morequickly responsive to heat in the fire zone of the outlet than saidfixed or determinate temperature device, said quickly responsive device.embodying by preference a pressure responsive device operative byincrease of air pressure generated at a greater thana predetermined oradjusted rate by the heating of air in the fire zone of the outlet,

More specifically stated, the object of our invention in its preferredform is to permit the main control valve to function in the usual wayupon a sudden drop in pressure in the dry pipe system due, for instance,to the operation of a sprinkler head and also to cause the. said controlvalve or other valve controlling the. supply of fire extinguishingmedium to the systemto 1927. SerialNo. 163,629 ((21. 169-1 1),

function throughanincrease in air pressure consequent upon the heatingeffect of fire on said piping. in, the area to be: protected, therebycausing the fire extinguishing medium to be supplied to. the system.before it could be otherwise supplied as the consequence of the openingof the automatic sprinkler head or other thermostatically controlledoutlet which cannot act until the'sol'der link or other thermostaticmeans controlling the sprinkler or other outlet has absorbed suificientheat to cause it to function in the usual way.

Oneof the usual objections to the dry pipe system is. that time is.required for passage of the fire extinguishing medium through thesystem. to the outlet, a disadvantage which can be overcome by theadoption of the system known as thefwet. pipe system in which water isalways present in the piping ready to issue immediately on the fusing ofa head or functioning or other thermostatically controlled outlet; butin such system. the. objection ispresent that the water is liable to.freeze. in the piping while, on the contrary, no such difficulty ispresent. in the case of. the dry pipe system wherein the fireextinguishing medium is excluded. from the piping until the occurrence.of fire.

By our present invention the advantages of the dry pipe. system asrespects non-freezing can. be. attained while at the same time, owing tothefunctioning of. the control valve before the thermostaticallycontrolled sprinkler head or other outlet would otherwise cause it tofunction, the practical advantage of the wet pipe system in respect toprompt discharge of the fire extinguishing medium on the occurrence offire can be retained.

Further our-invention consists in the combination of distributing pipesfor the fireextinguishing. medium, a thermostatically controlledsprinkler head v connected therewith, a valve normally held closed bypressure of air in the piping andcontrolling the supply of fireextinguishing medium thereto, said valve acting on relief of thepressure due to the opening of said sprinkler head, supplemental meansresponsive to thermostatic action and operating thermostatically morepromptly than the thermostatic control for the sprinkler head and means.controlled thereby for causing the dry-pipe valve to function before thesprinkler head opens or functions under its own thermostatic control toopen said valve.

Our invention. consists further in the combination in a dry pipe systemof means responsive to a drop in the air pressure therein for causingthe The invention also consists specifically in the combination with thesame valve which controls the supply to the distributing system and thatordinarily functions by decrease of air pressure therein, of meansresponsive to anincrease of the air pressure in the system due to heatin the fire area for also causing-said valve to open.

Our invention also consists broadly in the combination with normallyinactive supply means for supplying a fire extinguishing medium to thepiping and normally subject to pressure of fluid in said piping and heldinactive by said pressure but adapted to come into action on the reliefof said pressure, of an outlet in the fire zone normally closed butadapted to open and relieve said pressure and cause the supply means toact and means for causing said supply means to function subject to thecontrol of a pressure-responsive device responsive to increase of airpressure increasing at a greater than a predetermined or adjusted rateand produced by heating of the air in the fire zone.

In carrying out our invention we prefer to employ a pressure modifyingor equalizing vent adapted to neutralize changes of pressure of airincident to normal or regular changes of temperature in the particularsituation'in which the device is used. Saidequalizing vent issorestricted or adjusted however that the heat due'to a fire will resultin expanding the air sufficiently to produce the desired operating orcontrolling pressure or force.

The invention also consists in the specific combinations of devices andapparatus more particularly described in connection with theaccompanying drawing for effecting the general purposes of our inventionand in other details of construction and combinations of parts employedfor replenishing or maintaining the normal air pressure in the drypiping.

The accompanying drawing shows in partial vertical section and sideelevation an apparatus embodying our invention in one of the forms itmay take in practice.

Assuming that the invention is carried out in connection with water asfire extinguishing medium, the main water supply pipe thereof isindicated at 1 while 2 indicates a suitable manually controlled gatevalve for shutting off the supply of water to the apparatus at will. At3 is indicated a valve chamber of an automatic,

differential, main valve adapted to function on relief of the ordinarilymaintained pressure in the main distributing pipe '7 and its branches.Said valve is here shown as of the ordinary differential type and ashaving a clapper or valve 4 held to its seat against any pressure ofwater in the main 1 by means of a disk, clapper -or valve 5 hinged at 6and suitably connected-to the valve 4 so that the superior pressure ofthe fluid in the chamber 3 will normally keep the water valve 4 on itsseat. As shown, the valve 5 has, as ordinarily, a larger surface areaexposed to pressure of the air than the pressure area of 4 exposed towater, thus insuring the retention of valve 4 on its seat under thenormal conditions of pressures in the device 1 and 7.

zone of the sprinkler.

The main pipe 7 of the piping system is connected to the usual pipeshaving outlets thermostatically controlled, one of such outlets beingindicated at 8 as a usual sprinkler head thermostatically controlled andof typical form wherein an outlet valve is normally held closed but isadapted to open when released through the melting of a fuse andthereupon opens. As these devices and the arrangement of the system areof conventional form and well understood, they need not be furtherdescribed.

The functioning of the valve 4 in the usual way of the dry pipe systemoccurs when an outlet of the system is opened by the action of thethermostat thus relieving the air pressure on valve disk or clapper 5and permitting any superior pressure then existing on valve or clapper 4to open the same and throw back the valve 5 so that the fireextinguishing medium may pass freely from 1 to '7. V

' According to the preferred manner of carrying out our presentinvention the admission of the fire extinguishing medium to the piping 7through the action of the valve 4 or any other controlling valve may bealso brought about through the force of expansion of a heated'confinedbody of air exposed to heating in the fire 7 As an example of ourinvention we show how we may employ the body of air in the main tubing 7for this purpose, said body of air being however normally under positivepressure for the special purposes herein described. The heating of saidair acts to expand thesame and increased force of expansion or ofpressure then serves as the controlling force for the supplemental valvecontrolling means.

One of the ways in which the force of expansion of the heated air may beutilized for causing the main valve to open is by the admission of fluidpressure into the space 3 beneath the element 5 of the differentialvalve so as to destroy the differential condition by force assisting thetendency ofthe valve 4 to open under the pressure normally applied toit. The increase of pressure in the chamber 3' consequent upon theincrease of pressure in the pipe 7 of the system due to heating of theair in said pipe or its connections may be brought about by devicesconstructed and functioning as follows: I

At 10 is shown a chamber or enclosure connected by pipe 9 with thepiping 7 and containing a diaphragm 13 exposed to the air pressurewithin said chamber. Said diaphragm when moved under the effect of anabnormal pressure,

serves to'open a valve 19 and thereby open communication between thechamber 3 and a suitable source of air pressure through a pipe 20.Conveniently the pressure of air for acting on the valve disk 5 may bederived from the air in "the chamber 10' and the piping and valve areshown arranged for that purpose. The diaphragm 13 is flexibly supportedin the position shown which is its normal one, by suitable springsupport '14 or by other means, and may have a flange on the chamber 10and an upper section 11 thereof as indicated. In order that the pressureresponsive diaphragm 13 may be caused to act only when pressure of airheated and expanded in the fire zone occurs at a'greater than apredetermined or adjusted rate we provide a compensation consisting'ofan outlet passageway of restricted size operating as a compensating ventor escape for any pressure accumulating against the diaphragm to operatethe same its edges secured in position or clamped between and acting torender the diaphragm inoperative under pressure upon the controlmechanism for the valve or other supply means unless the pressureaccumulates or rises at a greater than a predetermined or adjusted rateunder the effects of expanding air heated and expanded in the fire zoneand in communication with the space beneath the diaphragm. At 12 isindicated the pressure modifying or compensating vent or passagewayhereinbefore referred to. Said passage is connected with the chamber 10,as shown and permits air under pressure to pass from 10 into anexpanding chamber 11 and thus relieve to a predetermined extent theforce of expansion exerted upon diaphragm in chamber 10. When the airpressure becomes sufficient said diaphragm acts upon the controllingdevices as will be presently described. As will be seen the use of theclosed expansion chamber prevents waste of pressure of air in the systemthrough the vent 12. By using expansion chamber 11 above the diaphragmair pressure in the section 11 will act upon the diaphragm in oppositionto the pressure within the body or section 10 but said pressures arenormally balanced owing to the fact that there is communication fromchamber 10 to chamber 11 through the pipe in which the compensatingdevice is located so that, after establishment of the air pressure inthe chamber 10 from the normal pressure delivered thereto throughconnection 9 with the system 7, the same pressure will exist above thediaphragm, being established therein through the bypass 12. Normal airpressure being thus existent both above and below the diaphragm, saiddiaphragm maintains its position so long as the normal pressure ismaintained in the piping 7 and its connections; but upon an increase ofsaid normal pressure at some rate which cannot be compensated for by therestricted bypass opening or compensating vent 12, the pressure belowwill become superior to that above and the diaphragm will be lifted. Thelifting of the diaphragm thus produced results in the opening of thevalve 19 and this action may be effected by the devices to be nowdescribed. These devices are also so constructed that a decrease ofpressure in the system which frees the control valve by diminishing thepressure on the disk or clapper 5 will be supplemented in its action byan increase in pressure in the chamber 3'.

Referring now to the devices whereby the valve 19 may be opened by theincrease of pressure in 7 and preferably also by the decrease ofpressure therein: 16 indicates a rocker arm or lever suitably pivotedwithin the chamber on a pivot at 17 and deriving motion from thediaphragm 13 by a flexible member 15 connected at one end to a frame ormember carried by the diaphragm, and to be presently described more indetail, and connected at its other end to the rocker arm or lever 16 sothat motion of the diaphragm away from normal position either up ordown'will rock or turn the lever 16 in one direction or the other andcause one or the other of two arms or forks projecting therefrom toeither side of its pivotal point 17' to engage the weighted lever 17 andin either case to force the same to the left past the vertical linethrough its center of support, thus causing it to drop over to theposition indicated in dotted lines and to thereby open the valve 19.Upon motion of the diaphragm upwardly, the upper arm or fork 40 willengage and force the weighted lever 17 t0 the left. Upon movement ormotion of the diaphragm downwardly the armor fork 41 provided willengage the. weighted lever and. turn it in the required direction foroperation of the valve. The action of the lever 16 upon-the valve .19may be effected inv obvious fashion by an arm projecting from theweighted lever like the arm of a. bell crank and positioned underneaththe projection. extending laterally from the pivoted, weighted membercarrying the valve 19.

other means and the actuating arm occupies a position. normallybeneaththe projection from the valve carrying arm as shown, there beingpreferably some. play allowed at this point. so that the momentumrequired by the weighted lever 17in. falling after it passes the centermay serve to insure action of the valve.

Under normal conditions and with normal air pressure in the pipe 7 andits connections the parts so far described will be in the position shownand the main valve will be subjected to the pressure of the fluid in thedistributing pipe '7. Should a sprinkler or other outlet of the pipingsystem for thefire extinguishing fluid open, the pressure in'l, 9 and 10would more or less quickly fall and thediminution of pressure below thediaphragm not being equalized by the pressure above, owing to the timerequired for a corresponding diminution of pressure through the bypassor equalizing vent, the air pressure above the diaphragm will besuperior and will move the diaphragm 13 downward. This motion will betransmitted through the flexible member 15 causing the rocker or lever16 to rotate and force the. weight 17 and lever carried thereby to the.left by the engagement of the lower member of the fork carried by 16with said weight until the lever passes the center. The weight thenfalls and the lever engages and lifts the air valve 19. Fluid such asair'under pressure from chamber 10 or other source thereupon enters pipe20 and, reaching chamber 3", exerts pressure beneath the valve member 5'which conspires with the pressure. under member 4 to lift or open thevalve. This action is assisted by the simultaneous diminution of thenormal pressure on the upper face of the disk or clapper 5 consequentupon the diminution of the air pressure in the distributing system. As aresult thereof the automatic action of the main dry pipe valve in thenormal. manner of this type of valve and consequent upon diminution ofpressure in the system is supplemented and assisted by the action of asupplemental pressure admitted through pipe 20 to the chamber 3, and themain valve 4 is thereby quickly and. positively opened.

It should be understood that the chamber 3' is, in this particularembodiment of our invention, the one ordinarily employed with automaticdry pipe valves and known as the intermediate or atmospheric chamber.The normal purpose of this supplemental chamber is to allow any'leakagethat might occur from above the member or clapper 5 or from below theclapper or member Therefore said Said valve.19*is'normally seated by itsown weight or r ball 21' which normally lies at the bottom of the elbowor trap of the ball drip as shown and inposition to allow slight flow ofwater or air to pass over the top of the ball and out of the dripthroughthe raised nozzle or spout thereof.

In the event of fire or the existence of conditions requiring theoperation of the main control valve to permit the passage of fluid from1 to 7, the sudden rush of either water or air will cause the ball toroll upward to the constricted section of the spout-shaped body oroutlet of the ball drip and close the outlet. When the air is admittedto the pipe 20 the sudden rush thereof will first move the ball 21' andclose the outlet and then will fill the section or chamber 3 with airunder pressure which will assist the liquid pressure tending to open thevalve 4, the tendency to such opening being at such time opposed -to aless extent by the clapper or member 5 owing to the simultaneousdiminution of pressure above the same consequent upon the opening of anoutlet in the dry pipe system. The con- .joint effect of these actionsis to establish the .want of balance between the forces tending to closeand to open the main valve and the latter thereupon opens to permitpassage of the fluid in the usual way.

, We will now describe the action of the apparatus having reference tothe operation referred to at the beginning of the specification inexpediting the opening of the main valve by an increase of pressure ofair exposed to the influence of the fire or other thermic conditionrequiring the application of a fire extinguishing medium at the dangerpoint. When the air in the dry pipe system is'heated at the danger zoneit immediately expands and the pressure is quickly communicated throughpipe 7 to thechamber 10 and diaphragm 13 or other means responsive tochanges of fluid pressure. Inasmuch as an equalization of the pressureabove and below the diaphragm through the bypass or compensating ventcannot quickly take place and inasmuch as the dry pipe itself and theattachments, such as chamber 10 and its devices, are preferably housedto prevent the parts from freezing or being lowered abnormally intemperature, the air pressure thus caused to increase under diaphragm 13will lift the same. This motion is transmitted through flexible member15 thus lifting the arm of the lever 16 to which it is attached insteadof depressing the same. The upper arm or fork of such lever now engagesthe weight 17 and its lever moving the same to the left in the same waythat it was. previously moved by the action of the lower arm in the caseof the diminution of pressure. This motion effectuates the opening ofthe valve 19 as before-with the result that an increased pressureresults in chamber 3' and the balance of pressures which holds the mainvalve closed is in effect disturbed so that the valve will open underthe effect of the pressure of the fluid in pipe 1.

At this time and under this condition it is quite obvious that when theair pressure from pipe 7 is taken around to the under side of the valveclapper 5 there results a practical balance of pressure on the two sidesthereof leaving the per side of the valve disk 5, holds the fluid valve4 normally closed. As will be obvious, by this operationthe main valveby which the extinguishing fluid is admitted to the piping can bebrought into action and the flow established or begun before the outlet,thermostatically controlled, will have opened. This results inexpediting the arrival of the fluid at the fire extinguishing outlet,which is, one of the main purposes of our invention.

From the foregoing it will be seen that the normally closed outletretained closed by the fuse will prevent the escape of the fireextinguishing medium accidentally or abnormally supplied to the pipingand whereby damage to property in the absence of fire will be preventedand that in case the fuse or fixed temperature device should fail tooperate promptly the supplemental control devices for the supply meanssuch as the main valve will be brought into action by the operation ofthe pressure responsive means acting through the influence of theconfined body of air subject to heating in the fire zone. Furthermore ifin the particular system described as embodying our invention impairmentof the normal air pressure in the piping should ensue from failure ofthe supply of air pressure to keep the air pressure in said piping atthe desired degree and if as the result thereof the main valve shouldopen the only result would be that the fire extinguishing medium wouldfill the distributing piping ready for ejection at the outlet ble thistobe done without causing either of the 1 .apparatus actions abovedescribed, we may employ the following means:

At 22 is indicateden air pump which can be 'manually or power. drivenand automatically controlled in any of the ways known in the art,

said pump being adapted to force air through check valve 23 and controlor gate valve 24, through pipe 25, into a chamber 26 the rigid wall ofwhich may be a part of the casting or body for chamber 10 as indicated.In a wall of said 25 tends to force the diaphragm to the left as shownin the dotted lines. A rod or stem connected to the diaphragm, as shown,and suitably guided at its rear end in the wall of the chamber 25carries at its forward end, or suitably connected or mounted on saidend, a notch or fork f member 33 between the arms of which a rearextension of the rocker arm or lever 16 is received when the stem movestoward the rocker or lever 16 under the effect of the pressure on thediaphragm 27. This notch or fork operates as a lock toprevent action ofthe lever 16 and connected parts during the process of replenishing theair.

Also mounted on the stem and movable therefore with the diaphragm underthe pressure in chamber 26 is a collar 29 acting in the fork end of abell crank lever 30, such bell crank lever having an arm carrying avalve 31 which controls an outlet from chamber 26 into the chamber 10 inobvious fashion. When the valve 31 is lifted by the pressure ondiaphragm 2'7 air supplied from the pump isallowed to enter the dry pipesystem. By the interlocking of the notched or forked end on the stem 28the excess pressure established by the pump is prevented from liftingthe diaphragm-and causing an operation of the device I its controlled oractuated thereby in a manner already described. The diaphragm andattached rocker arm or lever 16 are thus locked. until sufficient airpressure has been established, after which the pump may be stopped andthe control valve 24 is then closed.

At the end of this operation an excessof pressure on the under side ofthe diaphragm might exist from failure of the bypass to equalize thepressure quickly enough on the two sides of said diaphragm so that ifthe stem 28 should be .per-

mitted to recede on falling of pressure in the.

chamber 26, the device would be placed in condition to permit the rockerarm 16 to beactuated and thereby bring about a premature action of themain control valve.

To prevent such abnormal elTect we provide means connected with thediaphragm l3-for holding the stem 28 against receding sufiiciently tounlock the lever 16 when the diaphragm 13 is in lifted position due tosuch unequalized pressures. Such means comprise interlocking memberscarried respectively by the diaphragm and by. the stem andcomprising inone form of our inventiona depending member 34 attached to the diaphragmand provided with a lug 36 which engages a projection 37 on the stem 28when the diaphragm is in lifted position, thereby holding the stemforward in such position that it will prevent rotation of the rocker arm16 until the diaphragm 13 has assumed its normal position throughequalization of pressure in chambers .10 and 11. When this occurs theprojection 37 will be freed from engagement with the lug '36 and thediaphragm 27 may then recede under its own spring action and go tonormal position, thus freeing the rocker arm 16 so that it may performthe valve releasing actions previously described. After the air supplyto the pipe 25 is cut ofi by -valve 24 leakage from the chamber 10through valve 31 is prevented owing to the fact that, as the pressurediminishes, the stem 28 and diaphragm 27 in receding will close saidvalve 31. A guide 35 may be provided for the lower end of the member 34.

In our companion application filed April 20, 1926, Serial No. 103,189,we have described and claimed broadly a fire extinguishing systemwherein the outlets for the extinguishing medium in the fire zone arethermally controlled by suitable construction of thermostat and arenormally closed while the means for supplying fire extinguishing mediumto the piping leading to the outlets is itself under the control of anindependent thermostat more sensitive than the thermal means for theoutlet and comprising a thermostat operated by comparatively quick rateof rise of temperature, the organization being such that the said supplymeans are normally inactive but, under the control of their thermostatare called into action in advance of the opening of the outlet under itsown thermal action and we do not therefore, claim such an organizationbroadly in the present case.

What we claim as our invention is:-

1. In a dry pipe fire extinguishing system, a valve controlling thesupply of fire extinguishing fluid to the system responsive to decreaseof normal air pressure in the system due to the opening of an outlet forcausing said valve to operate and means for operating said valve uponsudden or abnormal rate of increase of the air pressure due to heatingof the same in the distributing system.

2. In a fire extinguishing system containing air under pressure, thecombination with a valve controlling the supply of the extinguishingmedium to the system and responsive to a drop in pressure in the systemfor causing said valve to operate, means responsive .to a rapid increaseof air pressure due to increase of temperature at an abnormal rate inthe area to be protected for bringing said valve into operation.

3. 'In a fire extinguishing system, the combination with a valvecontrolling the admission of a fire extinguishing medium to the systemand normally held closed against the pressure of the fluid supply by thenormal pressure of fluid in .the system and'means responsive to a suddenor abnormal rate of increase of the pressure in the system due toheating of the same for disturbing the balance of pressures on saidvalve to cause the same to open.

4. In a fire extinguishing system, a distributing pipe for the fireextinguishing medium, a differential automatic main valve, held normallyclosed by the pressure of air in the distributing pipe a chamber whereinpressure tends to unseat the valve and means for automatically admittingair pressure to said chamber upon sudden increase of air pressure in thepiping extending from the area to be protected to the main valve.

5. In adry pipe fire extinguishing system, the combination with a mainvalve having an atmospheric drip chamber and provided with an automaticcheck in the drip outlet, of means for automatically admitting air underpressure to said chamber, said means comprising pressure responsivemeans subject to the force of expansion of air abnormally heated in thedistributing system to expedite the opening of the main valve.

6. The combination with a main fiuid supply valve, of means for applyingunseating air pressure thereto through the controlling action of an airpressure responsive device a chamber containing air under pressureacting on said pressure responsive device, means for supplying air tothe chamber carrying air pressure acting on said pressure responsivedevice, and means for automatically locking said pressure responsivedevice out of action while the means for supplying air are acting.

7. The combination with the main fluid supply valve, of a supplementalvalve through which air pressure is supplied to unseat said main valve,a pressure diaphragm controlling the action of the supplemental valve,means for restoring air pressure in the chamber containing saidsupplemental valve, a restricted bypass connecting the spaces in whichpressures act oppositely upon said diaphragm and means for locking thediaphragm and its connected controlling devices subjected to pressurefrom said restoring means. 8. The combination with the main fluid supplyvalve, of a supplemental valve for applying pressure to unseat the same,a pressure diaphragm controlling the action of the latter valve, achamber containing said latter valve and normally containing air actingon one side of said diaphragm, means for supplying air under pressure tothe chamber containing said valve to replenish the same, a restrictedbypass connecting said chamber with a chamber on the opposite face ofsaid diaphragm and means subjected to the pressure of the air supply forholding the diaphragm and its connected controlling devices out ofaction While the air in the chamber is being replenished.

9. The combination with the main distributing pipe containing air underpressure, the main supply valve having a chamber and means connectedtherewith whereby air pressure in said chamber may act to cause thevalve to be unseated, a valve controlling the admission of air underpressure to said chamber, a diaphragm subject to variations of airpressure in the main distributing pipe of the system and having a bypassleading from the space on the side of the diaphragm subject to suchvariations of air pressure to a space in which the air acts with anopposing pressure, means connected with said diaphragm for opening thelatter valve, a pump for restoring the air pressure in the pipe systemand having communication therewith through the chamber carrying saiddiaphragm, a supplemental chamber containing a supplemental diaphragmoperatively associated with said diaphragm subject to the variations ofair pressure, a valve through which the pump is connected with the pipe,means connected with the supplemental diaphragm for opening said lastmentioned valve, and means carried by thelatter diaphragm for lockingthe said valve operated diaphragm means out of action during thereplenishing of the air supply.

10. The combination with the main valve of a fire extinguishing system,of means subject to variation of pressure in a chamber, means controlledby said pressure responsive means for supplying air under pressure tounseat the valve, means for restoring the pressure in the chamber ofsaid pressure responsive means, locking means locking said pressureresponsive means out of action by the pressure of the replenishing airsupply and means for automatically holding said locking means in lookingposition under the action of the increased pressure in the chamber ofthe aforesaid pressure responsive means.

. pressure restoring air to lock the pressure responsive diaphragm outof action and means connected with the latter for holding the lockingmechanism in looking condition when the pressure responsive diaphragmresponds to the replenished pressure.

12. The combination of a supply pipe for a fire extinguishing medium, amain valve for the supply pipe, a pressure diaphragm subject tovariation of normal air pressure in the main supply pipe, mechanismconnected therewith for operating an air valve, means for restoring thenormal air pressure, a supplemental air pressure diaphragm subject tothe pressure of pressure restoring air, means connected with the latterdiaphragm for locking the valve operating mechanism out of action andmeans connected with the firstnamed diaphragm for locking said mechanismin looking position.

13. In a fire extinguishing system, the combination with distributingpiping containing air under pressure and subject to heating effects inthe fire area or zone, a main valve controlling the admission of fireextinguishing fluid to the distributing piping, control mechanism forsaid valve, and a weighted actuating device for said control mechanism,said weighted actuating device being normally detained or held out ofaction and means responsive both to decrease of air pressure and toincrease due to heating of air in the fire zone for releasing saidweighted actuating device on movement of said responsive device ineither direction.

14. In a fire extinguishing system, the combination with air tubingcontaining air under pressure and extending from the fire zone or areato a point of control, a weighted actuatin device normally detained orheld out of action, a diaphragm subject on the one side to directpressure of air from said tubing and on the other to an opposing orindirect pressure derived through a restricted bypass around thediaphragm and means connected with said diaphragm for releasing saidweighted actuating device upon either increase or decrease of the airpressure in said tubing.

15. In a fire extinguishing apparatus, the combination substantially asdescribed of a main valve, a control valve controlling pressure uponsaid main valve to effectuate an opening thereof, piping extending fromthe fire zone and containing air expanded byheating efiect in said zoneon the occurrence of fire, a diaphragm subjected on the one side to adirect pressure of air therein, a restricted bypass around the diaphragmfor applying pressure to the opposite side of said diaphragm and meanscontrolled by said diaphragm on either rapid increase or decrease of thenormal pressure in the air piping for eifecting the operation of saidcontrol valve.

16. In a fire extinguishing system, the combination with air tubingcontaining air under pressure and extending from the fire zone or areato a point of control, a weighted actuating device normally detained orheld out of action, a diaphragm subject on the one side to directpressure of air from said tubing and on the other to an opposingorindirect pressure derived through a restricted bypass around thediaphragm and means connected with said diaphragm for releasing saidweighted actuating device upon sudden increase of the air pressure insaid tubing.

1'7. In a dry pipe extinguishing system, the combination with a supplyvalve, normally subject to fluid pressure in the system of asupplemental chamber wherein pressure of fluid tends to unseat thesupply valve, means operated by the force of sudden expansion of heatedair heated in the area to be protected and means controlled thereby foradmitting fluid under pressure to said supplemental chamber to cause thesupply valve to open.

18. In a fire extinguishing system, the combination with a control valvecontrolling the supply of fire extinguishing medium to the system, meanssubject to pressure of fiuid in said system and acting on said valve ina direction to hold the same closed and subject also to a decrease ofthe pressure therein due to the opening of an outlet and pressureresponsive means responsive to the force of expansion of a confined bodyof air due to sudden heating of the air under fire conditions forcausing said valve to open.

19. In a dry pipe fire extinguishing system, the combination with adifferential automatic water supply valve for the system subject tovariation of pressure in the system consequent upon the opening ofanoutlet of the system in the area to be protected and means subject tothe sudden force of expansion of air in the fluid distributing systemdue to heating in the fire zone and means controlled thereby forproducing on a face of said valve a pressure which will cause the sameto open.

20. In a fire extinguishing system, the combination with a pipe forcarrying the fire extinguishing medium to the outlet, a difierentialvalve in which the normal pressure of air in the pipe holds the sameclosed, and means for admitting air pressure to a chamber of said valvein which the pressure will tend to unseat the valve, said meanscomprising a control valve normally shutting oil the flow of air underpressure to said chamber, pressure responsive means in communicationwith the pipe responsive to sudden increase of pressure due to heatingunder fire conditions.

21. In a fire extinguishing system, the combination with a differentialvalve normally held closed by pressure of gas in the system, a chamberconnected with means for causing the valve to become unseated by theaction of pressure in said chamber, means for admitting fluid underpressure to said chamber comprising a valve normally closing theentrance of fluid to said chamber, pressure responsive means connectedto the system and means controlled therefor actuating said valve saidpressure responsive means being responsive to pressure generated at agreater than a predetermined or adjusted rate by heating of said air inthe fire zone.

22. In a dry pipe fire extinguishing system, the combination with adifierential main valve controlling the supply of fire extinguishingmedium to the system and having an atmospheric drip chamber providedwith an automatic check in the drip outlet, of means actuated by theforce of expansion of a confined body of air when heated forautomatically admitting air under pressure to said chamber when saidbody of air is abnormally heated and expanded in the fire zone to causesaid main valve to open.

23. In a dry pipe fire extinguishing system, the combination with a mainvalve having an atmospheric drip chamber and provided with an automaticcheck in the drip outlet, of means for automatically admitting fluidunder pressure to said chamber said means comprising a pressureresponsive means subject to the force of expansion of air abnormallyheated in the distributing system to expedite the opening of the mainvalve.

24. The combination with a main difierential valve for a dry pipe fireextinguishing system, of

a supplemental air chamber in which pressure of air acts on the mainvalve in a direction to tend to unseat said valve, a chamber connecteddirectly to the dry-pipe of the system and having pressure responsivemeans responsive to pressure generated by heating of air at an abnormalrate in the fire zone, a valve controlling a connection between saidchamber and the supplemental chamber of the main valve, a lever foropening the said connecting valve and means connected with the pressureresponsive device for actuating said lever upon movement of saidresponsive means in either direction.

25. In a fire extinguishing dry pipe system, the combination with themain valve, of a supplemental chamber for applying pressure tending tounseat the same, a valve controlling the flow of fluid under pressure tosaid supplemental chamber, pressure responsive means connecting withdevices for opening the latter valve in response to an increase of fluidpressure acting therein, means connecting said pressure responsive meanswith the main pipe of the system, said pressure responsive means beingprovided with a pressure modifying vent by which pressures on the samemay be equalized, said vent serving to delay the establishment of anequalized pressure when the pressure in the main pipe rapidly increases.

26. In a dry pipe system having a piping containing a confined body ofair under pressure, the combination with a main valve, means forsupplying unseating fluid pressure to said valve through a normallyclosed supplemental valve, pressure responsive means subjected to theforce of expansion of the confined body of air in the piping of thesystem and subject to abnormal temperatures in the fire zone and a leverconnected therewith and having two actuating members acting uponsuitable devices to cause the supplemental valve to open upon responseof said responsive means to the change of normal pressure above andbelow normal and due respectively to abnormal heating of the air in thefire zone and to opening of an outlet connected to the piping.

ERNEST A. LOWE. JOHN R. HAMILTON.

